Diffusion of Chiral Janus Particles in Convection Rolls

Abstract

The diffusion of an artificial active particle in a two-dimensional periodic pattern of stationary convection cells is investigated by means of extensive numerical simulations. In the limit of large Péclet numbers, i.e., for self-propulsion speeds below a certain depinning threshold and weak roto-translational fluctuations, the particle undergoes asymptotic normal diffusion with diffusion constant proportional to the square root of its diffusion constant at zero flow. Chirality effects in the propulsion mechanism, modeled here by a tunable applied torque, favors particle's jumping between adjacent convection rolls. Roll jumping is signaled by an excess diffusion peak, which appears to separate two distinct active diffusion regimes for low and high chirality. A qualitative interpretation of our simulation results is proposed as a first step toward a fully analytical study of this phenomenon.

arXiv commentTo be publish in Physical Review Research

References in corpus (7)

• The hydrodynamics of swimming microorganisms
• Microswimmers in Patterned Environments
• Nonlinear dynamics of a microswimmer in Poiseuille flow
• Self-propelled Janus particles in a ratchet: Numerical simulations
• Enhanced diffusion due to active swimmers at a solid surface
• Nonlinear response of inertial tracers in steady laminar flows: differential and absolute negative mobility
• Non-Gaussian Normal Diffusion in a Fluctuating Corrugated Channel